The subsequent claim about synthesis is not presented as self-evident but as a conclusion to be confirmed in §§18–20

If the sufficiency claim, and with it the reciprocity thesis, is denied, we need an alternative account of how §17 functions in the overall argument of the B-Deduction. It may be that the role of this section is largely to provide a characterization of an object that has a key role in the ensuing challenge to Humean associationism, and thereby initiates an argument from below. Kant’s proposal is that an object is “that in the concept of which a manifold of a given intuition is united” (B137). Th